Strength of Loop Connections between Precast Bridge Decks Loaded in Combined Tension and Bending

The paper presents a study of the load-carrying capacity of loop connections subjected to combined tension and bending. For such connections, the main design challenge in practice is to obtain a load-carrying capacity that is governed by yielding of the looped reinforcing bars (i.e., the U-bars) and not by fracture of the joint concrete. Unfortunately, reliable design models serving this purpose have not yet been published. Therefore, in this paper, a design-oriented plasticity model is proposed for the calculation of the N-M interaction diagram accounting for both failure modes. The Work is an extension of a model previously developed by the authors for the case of pure tension. In addition to the theoretical work, test results of connections subjected to combined tension and bending are also presented. Calculations according to the model have been compared with tests. Satisfactory agreements have been found.